The present invention relates to overhead doors. More specifically, the present invention relates to an overhead door that is guided along a predetermined path of travel by a pair of tracks and is operable to disengage from the tracks when exposed to force of a predetermined magnitude, thereby preventing damage to the door, tracks, and surrounding structure.
Overhead doors have long been used to occlude openings in structures such as warehouses, factories, and the like. In addition, impact-resistant overhead doors such as those illustrated in U.S. Pat. No. 4,676,293, issued to Hanssen, and U.S. Pat. No. 5,025,847, issued to Mueller, have been developed to absorb or otherwise reduce the destructive force of impacts to an overhead door, thereby preventing damage to the door and surrounding structure.
While these and other known doors have operated with some degree of success, they have several shortcomings. Specifically, the impact-resistant doors which are shown in U.S. Pat. No. 5,025,847, are unduly cumbersome and complex. Complex door designs, of course, greatly increase the cost of manufacturing and maintaining such doors. Further, known release assemblies used in doors, while finding usefulness with specific types of overhead doors, such as industrial roll-up doors, have not been rendered useful for all types of doors including doors manufactured from rigid, panels.
Known devices suffer from additional problems. They often fail to release under some conditions, thereby causing damage to the door or surrounding structure, or in the alternative, a workman must spend time with various tools to reset, or otherwise readjust the door following impact. Many doors release in a specific direction only. Consequently, significant damage to the door will result if force is applied from the opposite direction.
Therefore, it would be desirable to have an overhead door that reliably moves along a predetermined path of travel to selectively occlude an opening in a structure and that releases from an associated track when exposed to force of a predetermined magnitude, thereby substantially preventing damage to the overhead door, track and surrounding structure.